Apparatus for seaming the edges of glass sheets

ABSTRACT

Apparatus for seaming glass sheets having curved or irregular edges precut to the desired outline. The glass sheets are conveyed along a substantially horizontal path between two pairs of seaming units located at opposite sides of said path. Each unit employs an endless, flexible, abrasive belt disposed transversely at an angle to the conveyor means. The belt of one unit of each pair engages the upper corner of the adjacent peripheral edge of the glass sheet, while the belt of the other unit of the same pair engages the lower corner of the same edge of said sheet. The inner loop of the belt is trained about a pulley mounted to rotate about a substantially horizontal axis, while the outer loop of said belt is trained about a pulley driven about an axis inclined to the vertical. Each unit is mounted to swing as a pendulum toward and away from the path of travel of the glass sheets to follow the outline of said sheets, while the belt thereof is free to slide simultaneously along said inclined pulley, said movements of the belt being initiated and controlled by the upward thrust of the glass sheets upon the belt as said sheets move progressively past the same.

United States Patent [1 1 Jendrisak et al.

[ 1 Apr. 2, 1974 154] APPARATUS FOR SEAMING THE EDGES OF GLASS SHEETS[76] Inventors: Joseph E. Jendrisak, 986 Grace St., Northville, Mich.48167; Harold E. McKelvey, 14934 Maplewood Ln., Plymouth, Mich. 48170[22] Filed: Jan. 14, 1972 21 App]. No.: 217,738

Related US. Application Data [63] Continuation-in-part of Ser. No.91,967, Nov. 23,

1970, abandoned.

[52] US. Cl 51/139, 51/140, 51/147, 51/283 [51] Int. Cl B24b 21/16 [58]Field of Search 51/137, 138, 139, 140, 51/147, 283

[56] References Cited UNITED STATES PATENTS 1,365,583 1/1921 Brown51/147 2,637,951 5/1953 White 51/140 2,837,876 6/1958 Kocher 51/1402,969,624 1/1961 Castine et al.... 51/137 3,624,965 12/1971 Gepfert51/138 X Primary Examiner-Donald G. Kelly Assistant Examiner-Howard N.Goldberg Attorney, Agent, or Firm-William E. Nobbe 57 ABSTRACT Apparatusfor seaming glass sheets having curved or irregular edges precut to thedesired outline. The glass sheets are conveyed along a substantiallyhorizontal path between two pairs of seaming units located at oppositesides of said path. Each unit employs an endless, flexible, abrasivebelt disposed transversely at an angle to the conveyor means. The beltof one unit of each pair engages the upper corner of the adjacentperipheral edge of the glass sheet, while the belt of the other unit ofthe same pair engages the lower corner of the same edge of said sheet.The inner loop of the belt is trained about a pulley mounted to rotateabout a substantially horizontal axis, while the outer loop of said beltis trained about a pulley driven about an axis inclined to the vertical.Each unit is mounted to swing as a pendulum toward and away from thepath of travel of the glass sheets to follow the outline of said sheets,while the belt thereof is free to slide simultaneously along saidinclined pulley, said movements of the belt being initiated andcontrolled by the upward thrust of the glass sheets upon the belt assaid sheets move progressively past the same.

21 Claims, 21 Drawing Figures PMENTEDAPR 21914 SHEET 0F 9 PATENTEDAPR21914 3800.477

SHEET 7 [1F 9 PATENTEDAPR 2 I974 SHEET 9 BF 9 92 P9 3. Q8 38 K O: 37 OrvNC m: N: m: it 0: m9 9: as: ma Ami F a9 a9 AIME E: 4 iw 3: 2 9:

0 3 Fm: but mfl: 0 $2 PN:

This application is aCOntinuatiOmin-Part of application, Filed Nov. 23,1970, Ser. No. 91,967 (allowed Oct. 20, 1971) now abandoned.

BACKGROUND "OF THE INVENTION The present invention relates to the edgeseaming of glass sheets and more particularly to apparatus for seamingthe curved or irregular peripheral edges of glass sheets precut to theirdesired outline.

The apparatus of this invention finds particular use in the productionof laminated automotive Windshields, or the like, wherein, for example,pairs of glass sheets are cut to matching outlines, washed, dried andeach pair stacked on a bending mold for transport through a tunnel-likebending furnace wherein the glass is bent to the desired shape. Afterbending, the sheets of each pair are separated and a sheet ofthermoplastic material is inserted as an interlayer therebetween to forma glassplastic sandwich assembly. This latter assembly is then laminatedwith heat and pressure, to form the ultimate product to be installed ina frame to serve as an automotive windshield, or the like.

Unless the raw edges of the cut glass sheets are seamed, the edgesremain so sharp that operating personnel and others handling the sheets,such as those who install the ultimate product, are likely to be cut.Seaming by moving an abrasive surface against the edges of the precutsheets has been found to eliminate the sharp edges. This is alsoimportant in that, otherwise, there would be a tendency for smallparticles or chips of glass to spall off from the raw cut edges of theglass sheets and find their way between the two sheets during bendingresulting in the sheets being fused together. It is well known that inthe bending operation, the glass sheets draw apart or separate slightlyduring the preheating cycle and tend to draw the small particles orchips of glass between the sheets, resulting in defects in the ultimateproduct. Seaming of the glass sheet edges also reduces thermal shock andbreakage of the sheets during bending.

It is therefore an aim of this invention to provide improved apparatusfor seaming the cut edges of the glass sheets rapidly and efficientlyand in a continuous manner.

Another object of the invention is to provide seaming apparatusembodying a plurality of seaming units arranged at opposite sides ofmeans for conveying the glass sheets to be seamed along a substantiallyhorizontal path, said units operating independently of one another andeach unit being mounted for bodily swinging movement about asubstantially horizontal axis during seaming of the sheet edges toautomatically adjust itself to the outlines of said edges.

Another object of the invention is to provide a plurality of suchseaming units, each employing an endless, flexible, abrasive belt forperforming the seaming operation, and means for mounting the beltwhereby, upon bodily swinging movement of the unit as the belt followsthe outline of the sheet, the said belt will also be subjected to asecond movement independently of said swinging movement, said combinedmovements of the belt being initiated and controlled by the upwardthrust of the glass sheet upon said belt.

A further object of the invention is to provide in such seamingapparatus, means for mounting the endless flexible abrasive belt of eachunit including a pulley mounted to rotate about a substantiallyhorizontal axis and about which the inner loop of the belt is trainedand a second pulley mounted to rotate about an axis inclined to thevertical and about which the opposite loop of the belt is trained, thesaid belt being free to slide along said second pulley simultaneouslywith and independently of the bodily swinging movement thereof wherebyto effect a uniform seaming of the sheet edge.

A further object of the invention is to provide, in seaming apparatus ofthe above character, at least one pair of seaming units at each side ofthe path of travel of the glass sheets, with the endless abrasive beltsthereof being disposed transversely at an angle to the conveyor means,the belt of one unit being adapted to grind the upper corner of theadjacent peripheral edge of the sheet and the belt of the second unit ofsaid pair being adapted to grind the lower corner of said edge, andmeans for driving the belts such that the working run of the first beltmoves downwardly and outwardly away from the sheet, while the workingrun of the second belt moves upwardly and outwardly relative to thesheet to obtain uniformily smoothe corners free of sharp edges while atthe same time, carrying the particles of glass removed from the sheetedges away from the major surfaces of the sheet.

A still further object of the invention is to provide means for mountingthe seaming units so that they are readily adjustable to the seaming ofglass sheets of varying size and different outlines and also whereby theorientation of the endless belts with respect to the edges of the glasssheets may be readily varied.

DESCRIPTION OF THE DRAWINGS A typical embodiment of the presentinvention will be described for purposes of illustration rather thanlimitation. In the drawings which form part of the description of thisembodiment and wherein like reference numerals refer to like structuralelements:

FIG. 1 is a plan view of seaming apparatus constructed in accordancewith this invention,

FIG. 2 is a side elevation of the apparatus,

FIG. 3 is a transverse, vertical section taken on line 3-3 of FIG. 2,

FIG. 4 is a transverse, vertical section taken on line 44 of FIG. 2,

FIG. 5 is a side elevation of one of the seaming units,

-. FIG. 6 is a fragmentary perspective view of a portion of theconveyor,

FIG. 7 is a diagrammatic view of one of the driving pulleys indicatingthe sliding action of the abrasive belt along said pulley,

FIG. 8 is a detail view of the mounting for the idler pulley,

FIG. 9 is a transverse, vertical section taken on line 9-9 of FIG. 8,

FIG. 10 is a detail view of the support carriage for a seaming unit,

FIG. 11 is a transverse, vertical section taken on line 11-11 of FIG.10,

FIG. 12 is a diagrammatic view of a glass sheet and the relativepositions of the seaming units,

FIG. 13 is asimilar view of a glass sheet showing the way in which theabrasive belts engage and move along opposite edges of the sheet, and

FIG. 14 is a further diagrammatic view showing the relative operativepositions of the abrasive belts with respect to the edges of the glasssheet,

FIG. 15 is a diagrammatic plan view of a further embodiment of theinvention for seaming all four edges of the glass sheets in a continuousmanner,

FIG. 16 is a plan view of the sheet turning apparatus of this embodimentfor orienting the glass sheets to place other edges thereof in positionfor seaming,

FIG. 17 is a diagrammatic plan view showing the manner in whichsucceeding glass sheets are turned in opposite directions,

FIG. 18 is an end view of the sheet turning apparatus,

FIG. 19 is a fragmentary side view of the sheet turning apparatus,

FIG. 20 is a plan view of the apparatus for seaming the opposite endedges of the glass sheets, and

FIG. 21 is a vertical transverse section taken on line 21-2l of FIG. 20.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsand particularly to FIGS. 1 and 2, the apparatus of this inventioncomprises a conveyor means A for conveying the glass sheets S to beseamed along a definite horizontal path to and throughthe seamingapparatus B.

The conveyor means A includes three sections C, D and E, arranged inspaced end to end relation. The first or receiving conveyor section Cand the third or exit conveyor section E are of substantially the sameconstruction, each comprising two spaced, parallel, horizontal rails 20and 21 supported at their opposite ends by posts 22 and 23. Extendingtransversely between the rails 20 and 21 are a plurality of shafts 24,journaled at their opposite ends in bearings 25 carried by said railsand having fixed thereto a plurality of spaced disks 26 for supportingand conveying the glass sheets. The shafts 24 of each conveyor section Cand E may be driven in any suitable manner, such as by an endless chain27 trained over sprocket gears 28 keyed to one end of the shafts 24 andconnected by suitable means to a drive motor (not shown).

The middle or intermediate conveyor section D is spaced from both theentry and exit conveyor sections C and E to provide open areas F and Gfor receiving the seaming apparatus B. The intermediate conveyor sectionD is constructed in much the same way as conveyor sections C and E inthat it also includes spaced disks 29 fixed to transverse shafts 30 forreceiving the glass sheets from conveyor section C and delivering themto conveyor section E.

The inner endmost shaft 24' of the receiving conveyor section C isdriven by chain 33 trained about sprocket gears 34 (FIG. 1) on shaft 24'and the next ad-v jacent shaft. From the opposite end of this shaft 24',the adjacent shaft 30 of the middle conveyor section D is driven by achain 35 (FIG. 1). The shaft 30 then drives the associated shaft 30' bymeans of a chain 36, and a chain 36' trained about sprocket gears 37,one of which is mounted on the adjacent or first shaft 24 of the exitconveyor section E.

Above the disks 26 on the shaft 24' of receiving conveyor section C andthe disks 29 on the shafts 30 of middle conveyor section D, there areprovided disks that are adapted to hold the glass sheets S firmly on thedisks 26 and 29 therebelow. Thus, a plurality of disks 40 are fixed on atransversely disposed shaft 41 journaled at its ends in bearings 42.Each bearing 42 is carried by a plate 43 pivoted on a post 44 on therails 20 and 21 by a hinge 45. The plates 43 are supported by posts 46to maintain the disks 40 in light rolling contact with the disks 26.Adjustable weights 47 on rods 48, supported on a brace 49, serve toafford a suitable degree of downward thrust on the plates 43.

Hold-down disks 50 and 51 are also positioned above the disks 29 on theshafts 30 of conveyor section D, the disks 50 being fixed on a shaft 52journaled at its ends in bearings 53. Similarly, the disks 51 aremounted on a shaft 54 journaled in bearings 55. The bearings 53 aremounted on plates 56, while the bearings 55 are carried by plates 57.The plates 56 and 57 are pivotally supported in the same manner as theafore-mentioned plates 43. However, as illustrated in FIG. 6, toaccomodate the associated weights, the plates 57, in each case arelocated outwardly of the plates 56. With this relationship of thehold-down disks 40, 50 and 51, the glass sheets will be firmly heldagainst inadvertent lateral slipping while being acted upon by theseaming devices H and I of the apparatus B.

Each glass sheet S, as it traverses the receiving conveyor section C, iscarried between a pair of guide rollers 58 that are substantiallyequally spaced, in transverse relation, from the longitudinal axis ofthe conveyor A. The rollers 58 are supported by brackets 59 on atransverse bar 60 which is secured at its ends to the rails 20 and 21.The bar 60 is formed with aligned slots 61 (FIG. 1) through whichbolting means 62 are passed to lock each bracket 59 in desired positionto accomodate glass sheets of different widths.

The seaming apparatusB comprises a pair of seaming devices H and I,located at each side of the conveyor and positioned to operate withinthe open areas F and G of the conveyor means. Each pair of seamingdevices includes two seaming units 63 and 64, one being adapted to seamthe upper corner of the adjacent peripheral edge of the glass sheet andthe other the lower corner of the same edge of the sheet, as will bemore fully hereinafter described.

With particular reference to FIGS. 1, 3 and 5, each seaming unit employsan endless, flexible abrasive belt 65 for performing the seamingoperation. The inner loop of the belt is trained about a pulley 66 fixedto a horizontal shaft 67 vertically spaced from the conveyor A inwardlyof the side edges thereof, while the outer loop of the belt is trainedabout a pulley 68 keyed to a shaft 69 located at the side of theconveyor and arranged at an angle inclined to the vertical. The pulley66 is ordinarily an idler pulley, while pulley 68 is driven from a motor70 connected to the pulley shaft 69 by a suitable coupling 71.

The belt 65 may be of canvas or other tough, flexible material trainedabout the spaced pulleys 66 and 68 to provide a working run 72 and areturn run 73, and has its outside surface 74 coated with a suitableabrasive. Abrasive belts of this general character have previously beenused to grind the edges of glass sheets and it is customary to effectthe grinding action by bringing an edge of a glass sheet to be groundinto grinding engagement with the working run of the belt.

shaped bracket-76'forming an integral part of a structural frame 77,while the pulley shaft 69 is journaled in a bearing 78 at one end in theleg.79 of saidL-shaped bracket. The opposite end of shaft 69 isjournaled in a bearing 82 secured to the outer end of an arm 83 which isattached at its opposite end to the said L-shaped bracket 76. i i

The abrasive belt support means also includes an elongated support baror boom 85, forming a part of the structural frame 77, and secured atone end to the L-shaped bracket 76, the opposite end of said bar beingturned at right angles as at 86 (FIGS. 8 and 9) and having formedintegral therewith a flat plate 87. Secured to the bottom of the plate87, by bolts 88, is the base 89 of a mounting bracket 90 for supportingthe idler pulley 66.

The bracket 90 includes a wall 91 from the base 89 and has a pair oftransversely spaced ears 92 in which are carried the ends of a supportaxle 93. The axle 93 carries an arm 94 having lugs 95 formed at itsopposite or free end. The pulley 66 is carried on the shaft 67 by meansof bearings contained in the hub 96 (FIGS). As shown in FIG. 9, each lug95 is formed with an opening 97 through which the shaft 67 for thepulley 66 is passed. The ends of this shaft are adapted to be shiftedrelative to one another to initially locate the pulley 66, or otherwiseadjust the same, in order that the inner loop of the abrasive belt 65will be maintained in a centered running position on the pulley. To thisend, a bolt 100 is threaded through wall 101 of each lug 95 and theshaft 67 whereby, with the coaction of a spring 102, rotation of onebolt in one direction will compress the associated spring whilecontra-turning of the other bolt will allow expansion of the relatedspring.

The arm 94 also serves to obtain the desired degree of working tautnessin the belt and to permit convenient removal and replacement of saidbelt. For this purpose, the arm 94 is additionally formed with spacedears 104 in which a rod 105 is supported. This rod is cross-drilled andthreaded for a bolt 106. The bolt, passing freely through arm 94 and thewall 91 as well, is equipped with a handle 107 and,'between said arm andwall, carries a pair of lock nuts 108. Normal expansion of coil spring110, bearing by washers 111, against the wall 91 and nuts 108, tends bybolt 106 and rod 105, to urge the arm in such direction as to producetightening of the belt. Through the use of a handle 112, the arm 94 iscaused to swing reversely against the action of the spring 110, therebyproducing a slack in the abrasive belt to facilitate its removal fromthe pulley 66.

The boom or bar 85 of the frame structure 77 is reinforced toward thearm 83 by a strut 115 and additionally by a diagonally disposed brace116 from the bracket 76.

Fixed to the support bar 85 and the brace 116 adjacent the bracket 76,is one end of a substantially vertical hanger member 117, havingparallel legs 118, the upper ends of which are formed integrally withlegs 1 19 extending at right angles thereto and connected by a cross-bar120. The under surface of each leg 119 is equipped with a length of gearrack 121. The hanger member 117 is suspended from a support carriage Jhung from the horizontal I-beam 125 mounted transversely above theconveyor A from overhead beams or the like.

The supporting carriage J is best shown in FIGS. 10 and 11, andcomprises a base plate 126 on which are mounted two spaced pairs ofrollers 127-128 riding on the flanges 129-130 respectively, of I-beam125. The rollers 127-128 are fixed to stub shafts 131-132 respectively,journaled in bearings 133-134 located in the side members l35136supported on the base 126. The side members 135-136 are secured by bolts137-138 to a bar 139 each of which is secured by a bolt 140 to the baseplate 126. Between the side plates 141-142 of the base plate 126 islocated a vertically disposed plate 143 having a horizontal bar 144 atthe lower end thereof extending outwardly from both sides.

In mounting the hanger member 117, selected teeth of the gear rack 121are engaged with the end of the bar 144 such that the hanger members 117will be suitably balanced to dispose the respective frame 77 at theproper angle for orientation of the abrasive belt 65 with respect to thecorner of the glass sheet. In this regard, it is to be noted that, as inFIG. 5, while the belts are actively engaged with the corners of thesheet edges, the frames 77, in their entirety will be free to swing as apendulum, with the bar 144 serving as a fulcrum.

The carriages J are movable along the I-beams 125 by the pairs ofrollers 127-128 and are guided by pairs of rollers 146-147 on shafts148-149 carried by the side members 135-136. The rollers 146-147 are inrolling contact with the edge surfaces of the flanges 129-130 of theI-beam 125. The carriages J are locked against movement by toggle'clamps151, each having a handle 152 which operates a clamping lever 153 tosecure the carriage by means of a bolt 154 when engaged with the web 155of I-beam 125. When it becomes necessary to move the seaming devicescloser to, or away from, the conveyor according to the width of theglass sheets to be seamed, the handles 152 produce swinging of theclamping levers 153 whereby the bolts 1 154 will be released fromengagement with the web 155 of I-beam 125 to permit movement ofthe'carriages J.

When seaming glass sheets, the sheets are. moved horizontally onto theentry section C of the conveyor A (usually from a cutting machine or awashing machine) and thence forwardly between the two pairs of seamingunits 11 and I. As best shown in FIGS. 3 and 14, as the glass sheetpasses between the seaming units, the upper and lower corners of theadjacent peripheral edge A of the sheet is engaged by the working runs72 of the belts 65 of the seaming units 63, while the upper and lowercorners of the opposite peripheral edge B of the sheet are engaged bythe belts of seaming units 64. The abrasive belts are normallypositioned at an acute angel with respect to the edges of the glasssheets by the balacing action determined by the location of thesupporting gear racks 121 of hanger members 117 on the bars 144. Thebelts are thus normally urged into engagement with the sheet edges bythe hanger members which are free to swing as a pendulum about ahorizontal axis defined by the teeth of the gear racks 121.

The belts are driven in the directions indicated by the arrows 157 and158, also shown in FIGS. 3 and 14. More particularly, the belts aredriven in such directions that the working runs of the belts engagingthe upper comers of the sheet edges a and b move downwardly andoutwardly away from the sheet, while the working runs of the beltsengaging the lower corners of the sheet edges move upwardly andoutwardly away from the sheet. As a result, as the belts grindsucceeding portions of the sheet edges, as the sheets pass therebetween,they will effectively remove the sharp corners thereof to present smoothangle surfaces so that the glass sheets can be manually handled withminimum liability of scratching or cutting the hands of the operators.Likewise, by driving the belts in the directions described above, theywill serve to carry away the ground glass particles so that danger ofthem becoming attached to the surfaces of the glass sheets will beminimized. Further seaming of the sheet edges reduces the liability ofbreakage of the glass sheets during bending as well as minimizingspalling and chipping of the sheet edges with consequent damage to theglass sheets.

The arrangement of the abrasive belts not only facilitates grinding ofthe longitudinal side edges of the glass sheets but also permitsgrinding of the front and rear corner areas thereof as the said sheetspass between the seaming units. This is due to the fact that the belts,in passing around the two pulleys 66 and 68 are crosslapped so that theworking faces of the working runs of the belts are normally disposeddiagonally of the path of travel of the sheets as shown in FIG. 13. Thisinitial positioning of the belts with respect to the glass sheets alsogreatly facilitates separation of the belts of opposing units by thesheets as they move forward to engage the belts, thereby permitting easyentry of the sheets between the belts.

As the glass sheet moves forwardly as indicated by the arrow 159, on theconveyor, the angled width of the working runs of the belts 65 of units63 will be contacted first by the curved corner area causing theflexible belts to conform to said curved corner area, as indicated at din FIG. 13. This will be true whether the corner is curved, as shown, orsharp. As the sheet moves on, the belts 65 of units 64 will be initiallyengaged by the forward edge e of the sheet and willthen slide along saidedge to engage the corner area f of the sheet. Upon continued forwardmovement of the sheet the belts of units 63 and 64 will successivelycontact and grind opposite edges g and h of the sheet. During this time,the thrust of the glass sheet against the working runs of the beltsflexes or twists the glass contacting portions thereof into thepositions shown at 160-161 where they are substantially parallel withthe edges being ground. At the same time, the tendency of these portionsof the belts to return to their normal or diagonal positions relative tothe sheet edges will maintain them in intimate contact therewith, andassure full grinding action, regardless of whether the belts are actingon an edge that is straight, curved or of other longitudinal contour.This same tendency of the working runs of the belts to regain theirnormal angled positions, will cause them to maintain engagement with thefollowing corner areas j and k of the sheet as indicated at I and m inFIG. 13, to grind the same as the end of the sheet approaches and movespast the belts.

As pointed out above, the abrasive belt grinding tool of this invention,when properly mounted and positioned, will operate in the manner justdescribed to produce and/or finish both longitudinal side and comer edgeareas of the desired type, even on unusually large or irregularly sizedand shaped sheets.

As the abrasive belts are contacted by successively different portionsof the sheet edges, they will be subjected to two different andindependent movements which greatly facilitate and improve the grindingoperation. More specifically, the belts will be caused to swing bodilyinwardly and outwardly, depending upon the outline of the sheet edge,about a horizontal axis and, at the same time, will be free to slidealong the length of the drive pulleys 68.

With particular reference to FIG. 5, as the abrasive belt moves alongthe longitudinal sheet edge, the belt will be free to swing outwardly tothe full line position and then inwardly to the position indicated inbroken lines. Simultaneously with this swinging movement of the belt,the said belt will be free to slide vertically along the drive pulley68, as indicated in FIG. 7. This sliding movement is caused by thebalancing action of the frame 77 which produces the desired amount ofpressure of the belts on the edges of the glass sheet. This induces anupward thrust on the working run 72 of the belt with resulting slidingof the outer loop of the belt along the drive pulley. Thus, when theglass sheets first engage the belts, the initial thrust of the sheet onthe belts will be insufficient to swing the entire weight of the unitbodily about its horizontal axis and at this time the belt will quicklyrespond to the thrust of the sheet and slide along the inclined pulleyuntil the thrust becomes of such magnitude as to swing the entire unitoutwardly. The belt will continue to move up and down along the pulleysimultaneous with bodily swinging movement of the unit subject tovariations in the thrust of the sheet upon the belt which, in turn, isdependent upon and controlled by the outline of the sheet edge. When thepressure of the upward thrust on the belt is removed or lessened theouter loop of the belt will be permitted to return to normal position.Both the swinging movement and the sliding movement of the belt will becontrolled by the outline of the sheet.

As pointed out above, as the working runs of the belts move outwardlyand away from the ground corners of the sheets they will carry with themthe glass particles removed from the sheet edges. This direction ofmovement of the belts is extremely important in preventing ground offparticles of glass from becoming lodged on the flat surfaces of theglass sheets and thereby causing scratching or marring thereof. Also,there is the danger that some of such particles might find their wayinto the ultimate laminated product, resulting in defects therein andrejection thereof.

DESCRIPTION OF A FURTHER EMBODIMENT In the embodiment of the inventiondescribed hereinabove and illustrated in FIGS. 1 to 14, each glass sheetS is conveyed along the conveyor means A with the longitudinal dimensionthereof substantially parallel with the longitudinal axis of saidconveyor means such that the opposite edges g and h are treated by theseaming devices H and I. However, the present invention alsocontemplates an apparatus by which all four edges of the glass sheetsmay be seamed in a continuous manner.

This further embodiment is illustrated in FIGS. 15 to 21 and comprisesgenerally a conveyor means A1 along which the glass sheets are conveyed,with their shorter dimension substantially parallel with thelongitudinal axis of said conveyor means. The sheets are moved forwardlyby said conveyor means to the seaming apparatus B1 which effects theseaming of the opposite end edges e of the said sheets. Upon continuedmovement the sheets will be delivered to and acted upon by the sheetorienting apparatus P and turned or rotated approximately 90 andconveyed on the conveyor means A to the seaming apparatus B, which willtreat the opposite longitudinal edges g and h of the sheets, asdescribed in detail hereinabove.

Referring particularly to FIG. 15, a blank sheet of glass M is locatedon a cutting table N and a score line of the desired outline madetherein. The scored blank is next removed to a table on which theselvage outer areas, indicated in broken line, are broken away to give asheet of the desired pattern to be seamed. The pattern-cut sheet is thentransferred to the conveyor means A1 and delivered to the seamingapparatus B1, with the longer dimension of said sheet being transverselydisposedwith respect to the longitudinal axis of the conveyor to presentthe opposite end edges e of the sheet to the seaming apparatus B1.

In order to subsequently seam the longer side edges g and h of the glasssheet, it is necessary that the sheet be turned or oriented such thatthe longer dimension of the sheet will be positioned substantiallyparallel with the longitudinal axisof the conveyor means A. This isaccomplished by the orienting means P which swings the sheet from theposition indicated at the entry end of the orienting means P to theposition shown as it moves onto the conveyor means A.

it is further contemplated that alternate sheets will be turned inopposite directions, as indicated in FIG. 17. This is particularlyadvantageous when a pair of sheets are to be processed together and itis necessary to identify each pair as they are removed from the exit endof the seaming apparatus B. Thus the first sheet S1 will be swung in acounter-clockwise direction and the second sheet S2 in the opposite orclockwise direction. The sheet orienting device will be hereinafterdescribed in detail.

Referring particularly to FIGS. and 21, the conveyor means A1 includesthree sections C1, D1 and E1 arranged in spaced end to end relation. Thefirst or receiving conveyor section C1 and the third or exit conveyorsection E1 are of substantially the same construction, each comprisingtwo spaced, parallel, horizontal rails 120 and 121 supported at theiropposite ends by posts 122 and 123. Extending transversely between therails 120 and 121 are a plurality of shafts 124, journaled at theiropposite ends in bearings 125 carried by said rails and having fixedthereto a plurality of spaced disks 126 for supporting and conveying theglass sheets. The shafts 124 of each conveyor section Cl and E1 may bedriven in any suitable manner, such as by an endless chain 127 trainedover sprocket gears 128 keyed to one end of the shafts 124 and connectedby suitable means to a drive motor (not shown).

The middle or intermediate conveyor section D1 is spaced from both theentry and exit conveyor sections Cl and E1 to provide open areas F1 andG1 for receiving the seaming apparatus B1. The intermediate conveyorsection D1 is constructed in much the same way as conveyor sections Cland E1 in that it also includes spaced disks 129 fixed to transverseshafts 130 for receiving the glass sheets from conveyor section C1 anddelivering them to conveyor section El.

The inner endmost shaft 124 of the receiving conveyor section C1 isdriven by chain 133 trained about sprocket gears 134 (FIG. 20) on saidshaft 124. The adjacent shaft of the middle conveyor section D1 isdriven by a chain 135. This shaft of section D1 then drives theassociated shaft by means of a chain. A chain 136' trained aboutsuitable sprocket gears 137, one of which is mounted on the shaft 130and the adjacent or first shaft 124 of the exit conveyor section E1.

Above the disks 126 on the shaft 124' of receiving conveyor section C1and the disks 129 on the shafts 130 of middle conveyor section D1, thereare provided disks that are adapted to hold the glass sheets S firmly onthe conveyor disks 126 and 129 therebelow. Thus, a plurality of disks140 are fixed on a transversely disposed shaft 141 journaled at its endsin the bearings 142. The manner of mounting the bearings 142 is the sameas that for mounting the previously described bearings 42 for the shaft41. Likewise, the mounting of the hold-down disks and 151 of the middleconveyor section D1 is the same as for the hold-down disks 50 and 51.

Hold-down disks 150 and 151 are also positioned above the disks 129 onthe shafts 130 of conveyor section DI, the disks 150 being fixed on ashaft 152 journaled at its ends in bearings 153. Similarly, the disks151 are mounted on a shaft 154 journaled in bearings 155; With thisrelationship of the hold-down disks 140, 150 and 151, the glass sheetswill be firmly held against inadvertent lateral slipping while beingacted upon by the seaming devices H1 and ll of the apparatus B1.

The seaming apparatus Bl comprises a pair of seaming devices H1 and l1located at each side of the conveyor means Al and positioned to operatewithin the open areas F 1 and G1 of the conveyor means. Each pair ofseaming devices includes two seaming units 163 and 164, one beingadapted to seam the uppercorner of the adjacent peripheral edge of theglass sheet and the other the lower corner of the same edge of thesheet.

As in the case of the seaming units H and I, each seaming unit H1 and I1employs an endless, flexible abrasive belt 165 for performing theseaming operation. The inner loop of the belt is trained about a pulley166 fixed to a horizontal shaft 167 vertically spaced from the conveyorAl inwardly of theside edges thereof, while the outer loop of the beltis trained about a pulley 168 keyed to a shaft 169 located at the sideof the conveyor and arranged at an angle inclined to the vertical. Thepulley 166 is ordinarily an idler pulley, while the pulley 168 is drivenfrom a motor 170 connected to the pulley shaft 169 by a suitablecoupling171.

The belt 165 may, like the belts 65 described above, be of canvas orother tough, flexible material trained about the spaced pulleys 166 and168 to provide a working run 172 and a return run 173, and has itsoutside surface 174 coated with a suitable abrasive.

The motor 170. is mounted on the leg 175 of an L- shaped bracket 176forming an integral part of a structural frame 177, while the pulleyshaft 169 is journaled in a bearing 178 at one end in the leg 179 ofsaid L shaped bracket. The opposite end of shaft 169 is journaled in abearing 182 secured to the outer end of an arm 183 which is attached atits opposite end to the said L-shaped bracket 176.

The abrasive belt support means also includes an elongated support baror boom" 185, forming apart of the structural frame 177, and secured atone end to the L-shaped bracket 176, as previously described inconnection with FIGS. 8 and 9. The mounting 190 for the pulley 166 isalso identical to the aforementioned pulley 66.

Fixed to the support bar 185 is one end of a substantially verticalhanger member 1117 having parallel legs 1118, the upper ends of whichare formed integrally with legs 1119 extending at right angles theretoand connected by a cross-bar 1120. The under surface of each leg 1119 isequipped with a length of gear rack 1121. The hanger member 1117 issuspended from a support carriage .Il hung from the horizontal I-beam1125 mounted transversely above the conveyor A1 from overhead beams orthe like.

The supporting carriage J1 is of the same construction as carriage Jdescribed above, and comprises generally a base plate 1126 on which aremounted two spaced pairs of rollers 1127-1128 riding on the flanges ofl-beams 1125. Between the side plates of the base plate 1126 is locateda vertically disposed plate 1143 having a horizontal bar 1144 at thelower end thereof extending outwardly from both sides.

In mounting the hanger member 1 1 17, selected teeth of the gear rack1121 are engaged with the end of the bar 1144 such that the hangermembers 1117 will be suitably balanced to dispose the respective frame177 at the proper angle for orientation of the abrasive belt 165 withrespect to the corner of the glass sheet. With this type of mounting,the frames will be free to swing as a pendulum while the abrasive beltsare actively engaged with the corners of the sheet edges.

The carriages J1 are also movable along the I-beams 1125 by the pairs ofrollers 1127-1128 to move the seaming devices closer to, or away from,the conveyor according to the size of the glass sheets to be seamed. Thecarriages can be secured or released for movement by use of the toggleclamps 1151.

The abrasive belts 165 are driven by the pulleys 168 in the directionsindicated by the arrows 1157 and 1158 in FIG. 21. More particularly, thebelts are driven in such directions that the working runs of said beltsengaging the upper corners of the sheet edges move downwardly andoutwardly away from the sheet, while the working runs of the beltsengaging the lower corners of the sheet edges move upwardly andoutwardly away from the sheet. The advantages of driving the respectivebelts in the directions above described have been fully set forth abovein the description of the preferred embodiment of the invention.

The abrasive belts 165, like the belts 65 of seaming apparatus B, arecross-lapped in passing around the pulleys 166 and 168 so that theworking faces of the working runs of the belts are normally disposeddiagonally of the path of travel of the sheets. As the glass sheet movesforwardly, as indicated by the arrow 1159 in FIG. 20, the angled widthof the working run of the belt 165 of unit 163 will be contacted firstby the curved corner area f1 causing the flexible belt to conform tosaid corner area. Simultaneously, the belt 165 of seaming unit 164 willengage the leading corner area kl of the sheet. Upon continued forwardmovement of the sheet. the belts of units 163 and 164 will successivelycontact and grind the opposite end edges e and e1 respectively of saidsheet as well as the following corner areas cl and jl. During grindingof the sheet edges, the belts move freely inwardly or outwardly tofollow the edges of the sheet, while simultaneously, the belts can slidealong the pulleys 168 in the same mannet as the abrasive belts 65 ofseaming apparatus B, as described above.

After the end edges e and e1 of the glass sheet S have been seamed, thesheet moves from the conveyor A1 to the sheet orienting apparatus Pillustrated in FIGS. 16, 18 and 19. This apparatus comprises a conveyormeans R for receiving the sheet from the conveyor A1, said conveyormeans R including a framework 200 formed by spaced horizontallydisposed, longitudinally arranged bars 201 and 202 connected at theirrespective upper ends to vertically disposed posts 203 and 204.

The conveyor means is formed by endless chain belts 206 and 207supported by rollers 208 on tracks 209 and 210 on the bars 201 and 202.At one of their looped ends, the chain belts are trained about similiarsprockets 212 keyed on a shaft 213 that is journaled in bearings 214 onthe posts 203 (FIG. 18). One end of the shaft 213 is equipped with asprocket 215 that is adapted to be driven from a gear unit 216 by meansof a chain belt 217. The opposite looped ends of chain belts 206 and 207are trained about sprockets similiarly mounted on a shaft 218 journaledin bearings 219 attached to the posts 204.

The sheet supporting surface of the conveyor belts 206 and 207 is formedby channel members 225 mounted at their opposite ends by blocks 226 oneach of the belts and arranged in longitudinally spaced parallelrelation to one another. Spaced along each of the channel members are aseries of swivel-type casters 227 equipped with rollers 228. The sheetsupporting surface is thus formed by the rollers 228 that are adapted tofreely revolve about vertical axes afforded by the swivel action of thecasters.

Vertical rotation of the rollers 228, while in supporting relation witha sheet, is produced by turning or swinging of the sheet by means oforientation devices generally designated by the numerals 232 and 233that are supported above the conveyor R on a structural bar 234 carriedat its respective ends by floor-basedposts or channels 235 also securedto the bars 201 and 202. The orienting devices 232 and 233 have a plate238 and 239 respectively to which flexible tubes 240 and 241 areconnected by suitable pegs (not shown). The plate 238 (FIG.18) isattached to the lower end of piston rod 243 of a cylinder 244 mounted onthe bar 234 by a fixed base 245, the device 233 having an associatedcylinder 247 on a base 248.

The orienting devices are mounted to move in substantially verticaldirections by pairs of guide pins 250 and 251 secured at their lowerends to the plates 238 and 239 respectively and passing through thebases 245 and 248. The extent of downward movement of the plates 238 and239 can be adjusted by limiting collars 253, while the upper limit isreached when the plates are brought into contact with the bar 234.

As shown in FIG. 18, the tubes 240 of the device 232 are in the lowerposition in which the conveyed sheet will be engaged along the edge h ofits leading side. The tubes 241 of the orienting device 233, on theother hand, are at this time located in the upper position, with theirlower ends disaposed above the sheet.

As shown in FIG. 16, as the leading edge h of the advancing sheet isinitially engaged by the first of the tubes 240 and then the remainderof said tubes the sheet will be progressively swung in acounterclockwise direction through the broken line positions indicatedby the letters hl, h2, as illustrated in FIG. 16. And, as the cornerarea of the sheet is carried beyond the last of the tubes 240, the sheetwill have been oriented into a position in which the longer dimensionthereof is substantially parallel with the longitudinal axis of theconveyor R and in position to be moved onto the conveyor A where theopposite longitudinal edges g and h of the sheet will be subjected tothe seaming action of the seaming apparatus B.

As pointed out above, it is desirable to turn alternate glass sheetsupon entering the turning apparatus P in opposite directions to keep thesheets in pairs for further handling and processing. This'is shown inFIG. 17, in which the first sheet S1 is turned in a counterclockwisedirection by the orientation device 232, while the second or followingsheet S2 is swung clockwise by the orientation device 233. This isaccomplished by alternately raising and lowering the orientation devices232 and 233 such that when the orientation device 232 is in loweredoperating position the orientation device 233 is in position above andout of the path of travel of the sheet and vice versa.

More particularly, an electrically operated valve 256 is connected tothe cylinders 244 and 247 in such a manner as to produce retraction ofthe piston rod 243, attached to the plate 238, and projection of thesimiliar piston rod associated with the plate 239. Thus, the

valve 256 has a tubing piece 257 joined to the branch tubing elements258 and 259 at the tee fitting 260. The tubing element 258 connects tothe upper end of the cylinder 244, while the tubing element 259continues to the lower end of cylinder 247. Now, when an electriccontrol element 262 is energized the tubing 257 will be in opencommunication with a supply pipe 263.

Energization of the control element 262 is activated throughan electricsystem including a switch 265 having an arm 266. This arm is disposed inthe path of a glass sheet to cause timed sequences of action of theswitch 265 whereby the valve 256 will carry out the abovedescribedcourse of operation of the cylinders 244 and 247. The valve 256 is alsoconnected by tubing pieces 268 to tubing elements 269 and 270 at the teefitting 271 (FIG. 16). The tubing element 269 connects to the lower endof the cylinder 244 while the tubing element continues to the upper endof the cylinder 247.

Accordingly, when the switch arm 266 is released from the trailing edgeof the glass sheet, it causes the switch 265 to reverse operation of thecontrol element 262 whereupon the valve 256 will direct pressure fromthe supply pipe 263 to the tubing 268 and the tubing elements 269 and270 to the lower end of the cylinder 244 and the upper end of thecylinder 247. This reuslts in raising the tubes 240 of the orientingdevice 232 out of the path of travel of the next sheet while loweringthe tubes 241 of orienting device 233 into position to engage theforward edge of the following sheet. Upon reversal of the operation, theorienting device 233 will be raised and the orienting device 232 loweredso that the orienting devices 232 and 233 will engage the leading edgesof alternate glass sheets to turn or swing them in opposite directionsas shown in FIG. 17. As above pointed out, this alternate orientation ofsucceeding glass sheets permits a pair of sheets to be readilyidentified as they are removed at the exit end of the conveyor means Aof seaming apparatus B.

It will be understood, of course, that while the forms of the inventionherein shown and described constitute preferred embodiments of theinvention, they are not intended to illustrate all possible forms of theinvention. It will also be understood that the words used are words ofdescription rather than of limitation and that various changes may bemade without departing from the spirit and scope of the invention hereindisclosed.

We claim:

1. Apparatus for seaming the opposite edges of glass sheets cut to thedesired outline, comprising a conveyor means for conveying the glasssheets in a definite horizontal path, a pair of seaming units positionedat each side of the conveyor means,- each seaming unit including anendless, flexible abrasive belt for performing the seaming operation,said belt being disposed transversely at an angle to the conveyor meansto engage one corner of the adjacent peripheral edge of the glasssheets, means for mounting the endless belts of said seaming units forfree swinging movement about substantially horizontal axes independentlyof one another inwardly and outwardly relative to said conveyor means tocause the belts to follow the outline of the glass sheets, a pair ofspaced pulleys for each abrasive belt and about which the belt istrained, one of said pulleys being mounted opposite the plane of theconveyor means and the second pulley being mounted at the side of saidconveyor means, and means for driving one of said pulleys, said firstpulley being mounted to rotate about a substantially horizontal axis andsaid second pulley being mounted to rotate about an axis inclined to thevertical, said abrasive belt being free to slide along said secondpulley simultaneously with the swinging movement of the said belt.

2. Apparatus as defined in claim 1, in which the abrasive belt of oneunit of each pair is positioned to engage the upper corner of theadjacent peripheral edge of the glass sheet and the abrasive belt of theother unit of the same pair is positioned to engage the lower corner ofthe same peripheral edge of saidsheet.

.3. Apparatus as defined in claim 2, in which each.

endless abrasive belt has a working run and a return run, and includingseparate means for driving said belts in a direction such that theworking runs of the said belts move diagonally away from the plane ofsaid conveyor means.

4. Apparatus as defined in claim 3, in which the means for mounting theabrasive belts for free swinging movement also includes means for movingthe seaming units bodily transversely toward and away from said conveyormeans.

5. Apparatus as defined in claim 1, including means for supporting thepulleys of each unit in fixed spaced relation for rotation about theirrespective axes, and hanger means connected to said pulley supportingmeans for suspending the unit for free swinging movement.

6. Apparatus as defined in claim 2, including means for suspending eachseaming unit and providing a horizontal fulcrum about which said unit isfree to swing toward and away from the conveyor means.

7. Apparatus as defined in claim 5, in which said hanger means includesa substantially vertical hanger member secured to the means supportingthe pulleys in spaced relation, a carriage mounted above the hangermember, and interengaging means on said carriage and hanger memberproviding a fulcrum about which the unit is free to swing.

8. Apparatus as defined in claim 7, in which said interengaging meansincludes a horizontal member carried by said carriage and a gear rackcarried by said hanger member.

9. Apparatus as defined in claim 7, including means for supporting saidcarriage for movement transversely relative to said conveyor means toadjust the position of the abrasive belt with respect to the path oftravel of the glass sheet and for locking said carriage in adjustedposition.

10. Apparatus as defined in claim 2, including an elongated member forsupporting the pulleys of each pair in fixed spaced relation forrotation about their respective axes, a substantially vertical hangersecured at its lower end to said elongated member intermediate the endsthereof, a carriage mounted above said hanger for movement transverselyof the path of travel of the glass sheets, and interengaging parts onsaid carriage and upper end of said hanger providing a horizontalfulcrum about which the unit is free to swing toward and away from theconveyor means.

11. Apparatus as defined in claim 10, in which each endless abrasivebelt has a working run and a return run, and including separate meansfor driving said belts in a direction such that the working runs of thesaid belts move diagonally away from the plane of said conveyor means.

12. Apparatus for seaming the opposite edges of glass sheets cut to thedesired outline, comprising a conveyor means for conveying the glasssheets along a substantially horizontal path, a pair of seaming unitspositioned at each side of said conveyor means, each seaming unitincluding an endless, flexible abrasive belt for performing the seamingoperation, a pair of spaced pulleys for each abrasive belt and aboutwhich said belt is trained, one of said pulleys being mounted oppositethe plane of the conveyor means to rotate about a substantiallyhorizontal axes and the second pulley being mounted at the side of saidconveyor means to rotate about an axis inclined to the vertical, meansfor supporting the endless belts of said seaming units for free swingingmovement about substantially horizontal axis independently of oneanother inwardly and outwardly relative to said conveyor means to causethe said belts to follow the outline of the glass sheets, each abrasivebelt being free to slide along its respective second pulleysimultaneously with the swinging movement of the said belt.

13. Apparatus as defined in claim 12, in which the abrasive belt of oneunit of each pair of seaming units is positioned to engage the uppercorner of the adjacent peripheral edge of the glass sheet and theabrasive belt of the other unit of the same pair is positioned to engagethe lower corner of the same peripheral edge of said sheet, each belthaving a working run and a return run, and separate means for drivingsaid belts in a direction such that the working runs of the said beltsmove diagonally away from the plane of said conveyor means.

14. Apparatus as defined in claim 13, including separate means formounting each seaming unit, comprising an elongated member forsupporting the pulleys of each pair in fixed spaced relation forrotation about their respective axes, a substantially vertical hangersecured at its lower end to said elongated member intermediate the endsthereof, a carriage mounted above said hanger for movement transverselyof the path of travel of the glass sheets, and interengaging parts onsaid carriage and upper end of said hanger providing a horizontalfulcrum about which the unit is free to swing toward and away from theconveyor means.

15. Apparatus for seaming the edges of glass sheets, comprising aconveyor means for conveying the glass sheets in a definite horizontalpath, a pair of seaming units positioned at one side of said conveyormeans, each seaming unit including an endless, flexible abrasive beltfor performing the seaming operation, said belt being disposedtransversely at an angle to the conveyor means to engage one corner ofthe adjacent peripheral edge of the glass sheets, and means for mountingthe endless belts of said seaming units for free swinging movement aboutsubstantially horizontal axes independently of one another inwardly andoutwardly relative to said conveyor means to cause the belts to followthe outline of the glass sheets, a pair of spaced pulleys for eachabrasive belt and about which the belt is trained, one of said pulleysbeing mounted opposite the plane of the conveyor means and the secondpulley being mounted at the side of said conveyor means, and means fordriving one of said pulleys, said first pulley being mounted to rotateabout a substantially horizontal axis and said second pulley beingmounted to rotate about an axis inclined to the vertical, said abrasivebelt being free to slide along said second pulley simultaneously withthe swinging movement of the said belt.

16. Apparatus as defined in claim 15, in which the abrasive belt of oneunit of each pair is positioned to engage the upper corner of theadjacent peripheral edge of the glass sheet and the abrasive belt of theother unit of the same pair is positioned to engage the lower corner ofthe same peripheral edge of said sheet.

17. Apparatus as defined in claim 16, in which each endless abrasivebelt has a working run and a return run, and including separate meansfor driving said belts in a direction such that the working runs of thesaid belts move diagonally away from the plane of said conveyor means.

18. Apparatus for seaming the edges of glass sheets, comprising aconveyor means for conveying the glass sheets in a definite horizontalpath, a pair of seaming units positioned at one side of said conveyormeans, each seaming unit including an endless, flexible abrasive beltfor performing the seaming operation, said belt being disposedtransversely at an angle to the conveyor means to engage one corner ofthe adjacent peripheral edge of the glass sheets, means for mounting theendless belts of said seaming units for free swinging movement aboutsubstantially horizontal axes independently of one another inwardly andoutwardly relative to said conveyor means to cause the belts to followthe outline of the glass sheets, a second conveyor means positioned inadvance of said first conveyor means, a pair of seaming units located atone side of said second conveyor means for seaming the adjacentperipheral edge of the glass sheet as said sheet is carried therepast,and sheet orienting apparatus positioned between said first and secondconveyor means for turning said sheet approximately in its own plane anddelivering it to the said first conveyor means.

19. Apparatus as defined in claim 18, in which said sheet orientingapparatus includes means operable automatically for turning alternateglass sheets in opposite directions.

20. Apparatus for seaming the opposite edges of glass sheets cut to thedesired outline, comprising a conveyor means for conveying the glasssheets in a definite horizontal path, a pair of seaming units positionedat each side of the conveyor means, each seaming unit including anendless, flexible abrasive belt for performing the seaming operation,said belt being disposed transversely at an angle to the conveyor meansto engage one corner of the adjacent peripheral edge of the glasssheets, means for mounting the endless belts of said seaming units forfree swinging movement about substantially horizontal axes independentlyof one another inwardly and outwardly relative to said conveyor means tocause the belts to follow the outline of the glass sheets, a secondconveyor means located in advance of said first conveyor means, a pairof seaming units positioned at each side of the second conveyor means,each seaming unit including an endless, flexible abrasive belt forperforming the seaming operation, and sheet orienting apparatuspositioned between said first and second conveyor means and engageableby the sheet for turning said sheet approximately in its own plane anddelivering it to said first conveyor means.

21. Apparatus as defined in claim 20, in which said sheet orientingapparatus embodies means engageable by the leading edge of alternateglass sheets for turning said alternate sheets in opposite directions.

1. Apparatus for seaming the opposite edges of glass sheets cut to thedesired outline, comprising a conveyor means for conveying the glasssheets in a definite horizontal path, a pair of seaming units positionedat each side of the conveyor means, each seaming unit including anendless, flexible abrasive belt for performing the seaming operation,said belt being disposed transversely at an angle to the conveyor meansto engage one corner of the adjacent peripheral edge of the glasssheets, means for mounting the endless belts of said seaming units forfree swinging movement about substantially horizontal axes independentlyof one another inwardly and outwardly relative to said conveyor means tocause the belts to follow the outline of the glass sheets, a pair ofspaced pulleys for each abrasive belt and about which the belt istrained, onE of said pulleys being mounted opposite the plane of theconveyor means and the second pulley being mounted at the side of saidconveyor means, and means for driving one of said pulleys, said firstpulley being mounted to rotate about a substantially horizontal axis andsaid second pulley being mounted to rotate about an axis inclined to thevertical, said abrasive belt being free to slide along said secondpulley simultaneously with the swinging movement of the said belt. 2.Apparatus as defined in claim 1, in which the abrasive belt of one unitof each pair is positioned to engage the upper corner of the adjacentperipheral edge of the glass sheet and the abrasive belt of the otherunit of the same pair is positioned to engage the lower corner of thesame peripheral edge of said sheet.
 3. Apparatus as defined in claim 2,in which each endless abrasive belt has a working run and a return run,and including separate means for driving said belts in a direction suchthat the working runs of the said belts move diagonally away from theplane of said conveyor means.
 4. Apparatus as defined in claim 3, inwhich the means for mounting the abrasive belts for free swingingmovement also includes means for moving the seaming units bodilytransversely toward and away from said conveyor means.
 5. Apparatus asdefined in claim 1, including means for supporting the pulleys of eachunit in fixed spaced relation for rotation about their respective axes,and hanger means connected to said pulley supporting means forsuspending the unit for free swinging movement.
 6. Apparatus as definedin claim 2, including means for suspending each seaming unit andproviding a horizontal fulcrum about which said unit is free to swingtoward and away from the conveyor means.
 7. Apparatus as defined inclaim 5, in which said hanger means includes a substantially verticalhanger member secured to the means supporting the pulleys in spacedrelation, a carriage mounted above the hanger member, and interengagingmeans on said carriage and hanger member providing a fulcrum about whichthe unit is free to swing.
 8. Apparatus as defined in claim 7, in whichsaid interengaging means includes a horizontal member carried by saidcarriage and a gear rack carried by said hanger member.
 9. Apparatus asdefined in claim 7, including means for supporting said carriage formovement transversely relative to said conveyor means to adjust theposition of the abrasive belt with respect to the path of travel of theglass sheet and for locking said carriage in adjusted position. 10.Apparatus as defined in claim 2, including an elongated member forsupporting the pulleys of each pair in fixed spaced relation forrotation about their respective axes, a substantially vertical hangersecured at its lower end to said elongated member intermediate the endsthereof, a carriage mounted above said hanger for movement transverselyof the path of travel of the glass sheets, and interengaging parts onsaid carriage and upper end of said hanger providing a horizontalfulcrum about which the unit is free to swing toward and away from theconveyor means.
 11. Apparatus as defined in claim 10, in which eachendless abrasive belt has a working run and a return run, and includingseparate means for driving said belts in a direction such that theworking runs of the said belts move diagonally away from the plane ofsaid conveyor means.
 12. Apparatus for seaming the opposite edges ofglass sheets cut to the desired outline, comprising a conveyor means forconveying the glass sheets along a substantially horizontal path, a pairof seaming units positioned at each side of said conveyor means, eachseaming unit including an endless, flexible abrasive belt for performingthe seaming operation, a pair of spaced pulleys for each abrasive beltand about which said belt is trained, one of said pulleys being mountedopposite the plane of the conveyor means to rotate about a substantiallyhorizontal axes and the second pulleY being mounted at the side of saidconveyor means to rotate about an axis inclined to the vertical, meansfor supporting the endless belts of said seaming units for free swingingmovement about substantially horizontal axis independently of oneanother inwardly and outwardly relative to said conveyor means to causethe said belts to follow the outline of the glass sheets, each abrasivebelt being free to slide along its respective second pulleysimultaneously with the swinging movement of the said belt. 13.Apparatus as defined in claim 12, in which the abrasive belt of one unitof each pair of seaming units is positioned to engage the upper cornerof the adjacent peripheral edge of the glass sheet and the abrasive beltof the other unit of the same pair is positioned to engage the lowercorner of the same peripheral edge of said sheet, each belt having aworking run and a return run, and separate means for driving said beltsin a direction such that the working runs of the said belts movediagonally away from the plane of said conveyor means.
 14. Apparatus asdefined in claim 13, including separate means for mounting each seamingunit, comprising an elongated member for supporting the pulleys of eachpair in fixed spaced relation for rotation about their respective axes,a substantially vertical hanger secured at its lower end to saidelongated member intermediate the ends thereof, a carriage mounted abovesaid hanger for movement transversely of the path of travel of the glasssheets, and interengaging parts on said carriage and upper end of saidhanger providing a horizontal fulcrum about which the unit is free toswing toward and away from the conveyor means.
 15. Apparatus for seamingthe edges of glass sheets, comprising a conveyor means for conveying theglass sheets in a definite horizontal path, a pair of seaming unitspositioned at one side of said conveyor means, each seaming unitincluding an endless, flexible abrasive belt for performing the seamingoperation, said belt being disposed transversely at an angle to theconveyor means to engage one corner of the adjacent peripheral edge ofthe glass sheets, and means for mounting the endless belts of saidseaming units for free swinging movement about substantially horizontalaxes independently of one another inwardly and outwardly relative tosaid conveyor means to cause the belts to follow the outline of theglass sheets, a pair of spaced pulleys for each abrasive belt and aboutwhich the belt is trained, one of said pulleys being mounted oppositethe plane of the conveyor means and the second pulley being mounted atthe side of said conveyor means, and means for driving one of saidpulleys, said first pulley being mounted to rotate about a substantiallyhorizontal axis and said second pulley being mounted to rotate about anaxis inclined to the vertical, said abrasive belt being free to slidealong said second pulley simultaneously with the swinging movement ofthe said belt.
 16. Apparatus as defined in claim 15, in which theabrasive belt of one unit of each pair is positioned to engage the uppercorner of the adjacent peripheral edge of the glass sheet and theabrasive belt of the other unit of the same pair is positioned to engagethe lower corner of the same peripheral edge of said sheet. 17.Apparatus as defined in claim 16, in which each endless abrasive belthas a working run and a return run, and including separate means fordriving said belts in a direction such that the working runs of the saidbelts move diagonally away from the plane of said conveyor means. 18.Apparatus for seaming the edges of glass sheets, comprising a conveyormeans for conveying the glass sheets in a definite horizontal path, apair of seaming units positioned at one side of said conveyor means,each seaming unit including an endless, flexible abrasive belt forperforming the seaming operation, said belt being disposed transverselyat an angle to the conveyor means to engage one corner of the adjacentperipheral edge oF the glass sheets, means for mounting the endlessbelts of said seaming units for free swinging movement aboutsubstantially horizontal axes independently of one another inwardly andoutwardly relative to said conveyor means to cause the belts to followthe outline of the glass sheets, a second conveyor means positioned inadvance of said first conveyor means, a pair of seaming units located atone side of said second conveyor means for seaming the adjacentperipheral edge of the glass sheet as said sheet is carried therepast,and sheet orienting apparatus positioned between said first and secondconveyor means for turning said sheet approximately 90* in its own planeand delivering it to the said first conveyor means.
 19. Apparatus asdefined in claim 18, in which said sheet orienting apparatus includesmeans operable automatically for turning alternate glass sheets inopposite directions.
 20. Apparatus for seaming the opposite edges ofglass sheets cut to the desired outline, comprising a conveyor means forconveying the glass sheets in a definite horizontal path, a pair ofseaming units positioned at each side of the conveyor means, eachseaming unit including an endless, flexible abrasive belt for performingthe seaming operation, said belt being disposed transversely at an angleto the conveyor means to engage one corner of the adjacent peripheraledge of the glass sheets, means for mounting the endless belts of saidseaming units for free swinging movement about substantially horizontalaxes independently of one another inwardly and outwardly relative tosaid conveyor means to cause the belts to follow the outline of theglass sheets, a second conveyor means located in advance of said firstconveyor means, a pair of seaming units positioned at each side of thesecond conveyor means, each seaming unit including an endless, flexibleabrasive belt for performing the seaming operation, and sheet orientingapparatus positioned between said first and second conveyor means andengageable by the sheet for turning said sheet approximately 90* in itsown plane and delivering it to said first conveyor means.
 21. Apparatusas defined in claim 20, in which said sheet orienting apparatus embodiesmeans engageable by the leading edge of alternate glass sheets forturning said alternate sheets in opposite directions.